Automatic firearm



July 31, 1945.

H1. LIPPERT- ET AL AUTOMATIC FIREARM Filed April 30, 1942 v INVENTORSHANNS L/PPERT AND ERW/N HEPPERLE HTTYS.

Patented July 31, 1945 OFFICE AUTOMATIC FIREARM Hanns Lippert and ErwinHepperle, Zurich, Switzerland Application April 30, 1942, Serial No.441,159 In Switzerland July 12, 1941 9 Claims.

It has been proved to be necessary in automatic firearms to providedouble loading safety devices which lock the breech block movement if,for any reason whatsoever, during continuous firing a spent cartridgecase is not extracted from the cartridge chamber. The known doubleloading safety devices essentially comprise a feeler member whichmechanically locks the breech block movement if a spent cartridge caseremains in the cartridge chamber. These mechanical double loading safetydevices have proved to be very good and are in use in most firearms.Cases are known, however, especially in automatic firearms arranged inaircraft, in which the mechanical double loading safety device leads todifficulties; owing to the necessary effective connection of the feelermember arranged at the cartridge chamber to the breech block, since insome circumstances in firearms of this type the movement of the breechblock does not reach as faras the zone in the neighbourhood of thefeeler member. Further, the mechanical double loading safety deviceleads to an increase of the weight and of the moving parts of thefirearm, both of which are undesirable.

The object of the present invention is to provide an automatic firearmin which these difficulties are avoided.

According to the present invention, an automatic firearm is providedwith an electric double loading safety device using the trigger as alocking mechanism for the movement of the breech block mass, in whichthe feeler member at the cartridge chamber controls a contact or switchwhich is situated in the circuit of an electromagnet actuating thetrigger and, in the path of the breech block, there is provided afurther contact or switch controlled by the said breech block which canclose the circuit of the electromagnet when the contact of the feelermember is cut out.

The nature of the invention can be better explained by describing oneconstructional form which is shown by way of example, on the accompanying drawing, whereon:

Figure 1 is a diagrammatic representation of t-e firearm with trecartridge case not extracted from the chamber;

Figure 2 is the circuit diagram corresponding to the position of theparts shown in Figure 1:

Figure 3 is a view similar to Fig. 1 showing the firearm when thecartridge case is being extracted in the normal way;

Figure 4 is the circuit diagram corresponding to the position of theparts shown in Figure 3; and

Figure 5 is a circuit diagram for explaining the action of the contactor switch controlled by the breech block.

Referring to the drawing:

The barrel 2 with its cartridge chamber is fixed in the breech casing lby means of a bayonet joint 3. The reciprocating breech block 4 isrovided at its front end with an extractor claw 5 and at its rear endwith a hook 6 with which a hook I is adapted to engage, the hook I beingpressed down onto the hook 6 by a looking member 9 arranged to turn on apin 8. The locking member 9 is held in its locking position by a springIn and it is connected to a magnet l2 by a rod II. In the cartridgechamber there is provided a pin l3 acting as the feeler member of thedouble loading safety device and a pin 15 arranged in an insulating ringl4 acts upon the pin 13 in order to control the movement of a springcontact I6 toward and from a contact IT. The contacts l6 and I1 aresituated in a housing arranged on the breech casing. An insulatedcontact pin I9 and a counter contact 20 are also movably arranged on thebreech casing, the contact pin and the counter contact being situated ina housing 2|. The trigger contact is indicated at 22, 23 is the currentsource, and a spent cartridge case is shown at 24.

The circuit of the individual contacts is as follows: From the currentsource 23 one pole leads to the trigger contact 22 through a lead 25 andthence to the magnet i2. The other pole of the source 23 is connected tothe contact 20 through a lead 26 and to the contact I! through a lead28. The contacts l6 and H! are connected to the magnet l2 through theleads 2! and 29.

The manner of operation of the double loading safety device is asfollows: Assuming in all cases that the trigger contact 22 is closed andthe firearm therefore is firing continuously, at the beginning of thefiring no cartridge is in the cartridge chamber and hence the contact I6lies on the contact l1. When the trigger contact 22 is depressed thecircuit is closed through the leads 2t, 21, 28 and 29, the magnet I2 isenergized and the breech block 4 is released by the rocking of thebottom part of the member 9 to the left as shown in Figure 3, the hooks6 and I then disengaging. The positions of the contacts are shown inFigure 4. The breech block travels forwards and inserts a cartridge intothe cartridge chamber, whereupon the contact I6 is lifted from thecontact I! by the outward movement of the pins 13 and I5, which latteris forced outwards by the cartridge case. The circuit would then bebrckenand the magnet l2 de-energised, but in -order to avoid thisbreaking of the circuit, the contact l9 is arranged in the path, of thebreech blush I and the contacts l9 and 20 close the circuit on theforward run of the breech block 4, see Figure 5, so that the magnet 12is still .energised. If the cartridge case 24 is extracted after firing,the contacts l8 and H are closed and, in spite of the fact that thecontacts 19 and 20 are opened by the returning breech block 4, thecircuit remains closed as shown in Figure 4. If for any reason thecartridge case is not extracted, however, the contacts l6 and I! remainopen and on the recoil of the breech block, the contacts 20 and 2| arealso opened and the circuit is broken. The magnet I2 is thende-energised 'and the locking member 9 is. depressed by the spring illon to the hook I which, as shown in Figure 1, engagesin, the hook 6 onthe breech block and holds the breech block in the rearmost recoilposition. Even if the trigger contact 22 is depressed, firing is stoppedand it becomes apparent to the gunner that a fired cartridge caseremains in the barrel.

What w claim and desire to secure by Letters Patent is:

l. An electrically operated double loading safety device'i'or automaticfirearms comprising. in combination with the cartridge chamber and thebreechblock of .tlie firearm, locking mechanism ri' 'r r iea'sebiyholding the breech block in recoil positiiih, an electro-magnet arrangedto control sai flocking mechanism, a. feeler member at the c iqtridgechamber-in position to be actuated by t e. insertioneand extraction of acartridge, an

electric switch ,controlled by said .feeler member and arranged inthecircuit of the electro-magnet, a second feeler member arranged in thepath of the breech block, and a second switch controlled by thesaidsecond Ieeler member and arranged assent breech block being then lookedagainst movement at the end or its recoil upon opening of theelectromagnet circuit.

3. A firearm according. to claim 2, wherein the locking mechanismincludes a locking hook arranged to be actuated by the electro-magnet,the breech block having a hook arranged to be engaged by the firstmentioned hook, the locking mechanism acting, by engagement of thehooks, to lock the breech block against forwardmovement when the magnetcircuit is open.

. 4. A safety device for automatic firearms according to claim 1,wherein the feeler member at the cartridge chamber comprises a slidablepin which normally projects into the chamber, and a second, insulatedpin actuated by the first pin and arranged to control the associatedswitch.

5. A safety device for automatic firearms according to claim 1, whereinthe switch operated by the breech block is connected to an insulated pinwhich projects into the breech casing in the path of the breech block. I

6. A safety device for automatic firearms ac cording to claim 1,including a trigger switch arranged in said circuit to causeenergization of I the electro-magnet upon actuation thereof.

- 7. An electrically-operated safety mechanism for automatic firearmscomprisingyin combination with the breech block and cartridge chamber aof the firearm, locking mechanism for holding the breech block in itsrearward position, an electromagnet arranged to release the lockingmechanism upon energization thereof, means for returning the lockingmechanism'to breech block locking position upon de-ener'gization of theelectro-magnet, a pair of contacts at the cartridge chamber in positionto be actuated by the in- I sertion and extraction of a cartridge and asecond to close the circuit of the electro-magnet when the switchcontrolled'by the first feeler member is opened.- v

2. An electrically operated double loading safety device for automaticfirearms comprising, in combination with the cartridge chamber and thebreech block of the firearm, locking mechanism for releasably holdingthe breech block in recoil position, an electromagnet arranged tocontrol said locking mechanism, a ieeler member at the cartridge chamberand responsive to the presence and absence of a cartridge in suchchamber, an electric switch controlled by said teeler member andarranged in the circuit of the electro-ma'gnet, said switch, beingnormally closed in the absence of a cartridge in the chamber but beingopened when av partridge is inserted into the chamber, a second feelermember arranged in the path of the breech block, and a second switch,controlled by said second feeler member, said last mentioned switchbeing arranged to open and close said circuit and being normally openwhen the block is in retracted position but being closed by the breechblock when the latter is in an advanced position, the arrangement beingsuch that the electromagnet is deenergized if a cartridge case is notextracted from the chamber after firing, the

nism, a pair 01 contacts at the, cartridge chamber in position to beactuated by the insertion and extraction of a cartridge and a secondpair of contacts arranged along the path of movement of the breech blockand controlled thereby, the

two pairs of contacts being'arranged in para1lel in the circuit of theelectro-magnet whereby the electro-magnet becomes de-energized only whenI both pairs 01' contactsare open.

9. A safety device for automatic firearms according to claim 7,including a pair of contacts arranged at the trigger and in series withthe contacts at the cartridge chamber, whereby upon closing of thetrigger contacts, the electro-magnet becomes energized.

' HANNS LIPPERT.

